This invention relates to coating compositions and in particular to an aqueous coating composition of a graft copolymer.
Coating compositions of acrylic polymers are well known as shown by Crissey U.S. Pat. No. 2,934,509, issued Apr. 26, 1960 and provide finishes that have an excellent appearance and that are weatherable and durable but require the finish to be baked. Coating compositions of alkyd resins are also well known and have been used for many years as automotive and truck finishes. These finishes cure at ambient temperatures but do not have the excellent weatherability and durability of the above acrylic finishes. Simple blending of acrylic polymers and alkyd resins does not provide an optimum finish since these acrylic polymers and alkyd resins are not generally compatible. There is a need in the automobile and truck manufacturing industry and in the automobile and truck repair industry for a coating composition that will cure at ambient temperatures which represents significant savings of energy and for a composition that will provide a finish that has a high quality appearance and excellent weatherability and durability.
The novel coating composition of this invention utilizes a graft copolymer of an acrylic polymer and an alkyd resin that provides a finish that cures at ambient temperatures and has an excellent appearance, excellent physical properties and excellent adhesion to all types of coated and uncoated substrates. The composition has an added advantage of being readily formed into a water based composition.